LTC3878 Linear Technology Corporation, LTC3878 Datasheet - Page 3

• Manufacturer Part Number: LTC3878
• Description: Wide Operating Range No RSENSE Step-Down Controller
• Manufacturer: Linear Technology Corporation

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SYMBOL
t
V
V
V
INTV
INTV
TG/BG t
TG/BG t
Internal V
PGOOD Output
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: T
dissipation P
Note 3: The LTC3878 is tested in a feedback loop that adjusts V
achieve a specifi ed error amplifi er output voltage (I
ELECTRICAL CHARACTERISTICS
temperature range, otherwise specifi cations are at T
OFF(MIN)
SENSE(MAX)
SENSE(MIN)
RUN/SS
T
CC(UVLO)
CC(UVLOR)
J
= T
1D
2D
J
A
CC
is calculated from the ambient temperature T
+ (P
Regulator
D
as follows:
D
• 110°C/W)
PARAMETER
Minimum Off-Time
Valley Current Sense Threshold
V
Peak Current = Valley + Ripple
Minimum Current Sense Threshold
V
Forced Continuous Operation
RUN/SS Pin On Threshold
Soft-Start Charging Current
INTV
INTV
TG Driver Pull-Up On-Resistance
TG Driver Pull-Down On-Resistance
BG Driver Pull-Up On-Resistance
BG Driver Pull-Down On-Resistance
TG Rise Time
TG Fall Time
BG Rise Time
BG Fall Time
Top Gate Off to Bottom Gate On Delay
Synchronous Switch-On Delay Time
Bottom Gate Off to Top Gate On Delay
Synchronous Switch-On Delay Time
Internal V
Internal V
PGOOD Upper Threshold
PGOOD Lower Threshold
PGOOD Hysteresis
PGOOD Low Voltage
PGOOD Turn-On Delay
PGND
PGND
CC
CC
– V
– V
Undervoltage Lockout
Undervoltage Lockout Release
CC
CC
SW
SW
Voltage
Load Regulation
TH
).
A
and power
A
= 25°C. V
FB
CONDITIONS
I
V
V
V
V
V
V
V
V
Falling
Rising
TG High
TG Low
BG High
BG Low
C
C
C
C
C
C
6V < V
I
V
V
V
I
ON
CC
PGOOD
RNG
RNG
RNG
RNG
RNG
RNG
RUN/SS
RUN/SS
LOAD
LOAD
LOAD
LOAD
LOAD
LOAD
FB
FB
FB
to
= 0mA to 20mA
= 30μA
The
Rising
Falling
Returning
= 1V, V
= 0V, V
= INTV
= 1V, V
= 0V, V
= INTV
= 3300pF (Note 5)
= 3300pF (Note 5)
= 3300pF (Note 5)
= 3300pF (Note 5)
= 3300pf Each Driver (Note 5)
= 3300pf Each Driver (Note 5)
IN
= 5mA
Rising
= 0V
l
< 38V
IN
denotes the specifi cations which apply over the full operating
= 15V unless otherwise noted.
FB
FB
CC
FB
FB
CC
, V
, V
= 0.76V
= 0.76V
= 0.84V
= 0.84V
Note 4: The LTC3878E is guaranteed to meet specifi cations from
0°C to 85°C. Specifi cations over the –40°C to 85°C operating temperature
range are assured by design, characterization and correlation with
statistical process controls. The LTC3878I is guaranteed to meet
specifi cations over the full –40°C to 85°C operating temperature range.
Note 5: Rise and fall time are measured using 10% and 90% levels. Delay
times are measured using 50% levels.
FB
FB
= 0.76V
= 0.84V
l
l
l
l
l
5.15
–5.5
MIN
108
152
1.4
5.5
74
–1.2
–0.1
–7.5
0.15
TYP
220
133
186
–67
–47
–93
1.5
3.3
3.6
2.5
1.2
2.5
0.7
5.3
7.5
93
20
20
20
20
15
15
12
2
LTC3878
MAX
5.45
–9.5
300
165
119
224
1.6
3.9
9.5
3.5
0.4
±2
4
UNITS
3
3878f
mV
mV
mV
mV
mV
mV
μA
ns
ns
ns
ns
ns
ns
ns
μs
%
%
%
%
Ω
Ω
Ω
Ω
V
V
V
V
V